The antonyms for the word "tough nut" include words such as gentle, easy, weak, soft, and mild. A "tough nut" is often used to describe someone who is difficult to deal with or a problem that is challenging to solve. In contrast, a gentle person is someone who is considerate and empathetic. Easy refers to situations that are effortless or pose no difficulty. Weak implies a lack of strength or power. Soft indicates something that is smooth, easy to shape, or malleable. Mild describes something that is not strongly flavored or overly intense. These antonyms can be used to describe situations, individuals, or objects that are not problematic or challenging.